Abstract
OBJECTIVE: Resistance to activated protein C (APC resistance), caused by a single point mutation in the factor V gene (FV:R506Q), is a major risk factor for venous thrombosis. As the significance of this mutation among unselected outpatients with deep-vein thrombosis (DVT) is not established, we have studied its prevalence among consecutive outpatients attending the emergency room due to a clinically suspected DVT.
DESIGN, SETTING AND SUBJECTS: The FV:R506Q mutation was determined in 223 consecutive Swedish outpatients with clinically suspected DVT, and in 288 healthy controls. Using phlebography, the patients were classified as DVT-positive or DVT-negative.
MAIN OUTCOME MEASURE: The prevalence of FV:R506Q mutation.
RESULTS: The prevalence of the FV:R506Q mutation was 28% (28/99) in the DVT-positive subgroup (relative risk: 3.1; 95% CI: 1.7-5.5), and 23% (28/124) in the DVT negative subgroup (relative risk: 2.0; 95% CI: 1.1-3.6), as compared to 11% (32/288) in the control group. In the DVT-positive subgroup, the FV:R506Q mutation was most common among younger patients with primary thrombosis (47%) and least common among older patients with secondary thrombosis (19%). The high prevalence of FV:R506Q mutation among DVT-negative patients was associated with a high frequency of previous venous thrombosis. Thus, 46% (13/28) of the DVT-negative FV:R506Q carriers had a history of thrombosis, compared with only 22% (21/96) of the DVT-negative patients lacking the mutation (P = 0.01).
CONCLUSION: To sum up, the FV:R506Q mutation is present in more than a quarter of Swedish DVT-positive outpatients with clinically suspected DVT, indicating that APC-resistance is a major thrombotic risk factor contributing to the high incidence of venous thrombosis in Sweden.
Original language | English |
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Pages (from-to) | 379-385 |
Number of pages | 7 |
Journal | Journal of Internal Medicine |
Volume | 241 |
Issue number | 5 |
Publication status | Published - 1997 May |
Subject classification (UKÄ)
- Medicinal Chemistry
Free keywords
- Adult
- Aged
- Aged, 80 and over
- Case-Control Studies
- Factor V
- Factor Va
- Female
- Heterozygote Detection
- Humans
- Male
- Middle Aged
- Outpatients
- Phlebography
- Point Mutation
- Prevalence
- Protein C
- Thrombophlebitis
- Journal Article
- Research Support, Non-U.S. Gov't